We continue to improve our second generation optical trapping microscope, specifically tailoring it for use in feedback-tracking experiments. In the past year we have developed a new method for sensing particle displacement in the optical trap which is insensitive to the position of the trap in the sample, a major boon for particle tracking applications, among others. In addition, we are modifying the instrument such that the trap position is servoed by computer controlled acousto-optic modulators, adding great versatility to the manner in which we can track and manipulate particles. These additional capacities complement the capability we already have for combined trapping, widefield fluorescence imaging, and DIC microscopy, allowing us to examine the dynamics of single proteins on the cell surface while also imaging the underlying cellular and related membrane structures. As before concurrent laser scanning confocal or two-photon microscopy and optical trapping remain quite possible.